using System;

using System.Linq.Expressions;

using System.Reflection;

​

public class Foo{

    public string Bar {get;set;}

    public object Baz { get; set; }

    public object Boo; // field

    public object Baa() => 100; // method

}

​

public class Program

{

    public void Main()

    {

        var myFoo = new Foo { Baz = 5 };

        myFoo.Evaluate(f => f.Bar);

        myFoo.Evaluate(f => f.Baz);

        myFoo.Evaluate(f => f.Boo);

        myFoo.Evaluate(f => f.Baa());

    }

}

​

public static class ObjectExtensions{

    public static void Evaluate<T>(this T obj, Expression<Func<T, object>> expr){

        var prop = (expr.Body as MemberExpression)?.Member as PropertyInfo;

        var val = prop?.GetValue(obj);

        if (val != null) {

            Console.WriteLine($"{prop.Name} is of type {prop.PropertyType} containing a {val.GetType()} with value {val}");

            return; // yay!

        }

        if (prop == null)

            Console.WriteLine($"{expr.Body} is not a PropertyExpression, but a {expr.Body.GetType()}");

        else

            Console.WriteLine($"{prop?.Name} is of type {prop?.PropertyType} containing NULL");

    }

}

​